Abstract Hepatocellular carcinoma (HCC) remains a leading cause of cancer-related mortality worldwide. Ferroptosis induction represents a promising therapeutic strategy, but its efficacy is constrained by tumor heterogeneity, particularly the relative resistance of epithelial cancer cells to ferroptosis inducers. In this study, we explore the mechanisms of epithelial HCC cells (EC) acquire resistance to ferroptosis. Transcriptomics and metabolomics analyses revealed that the cysteine and methionine metabolic pathway is associated with the resistance of EC to ferroptosis inducer imidazole ketone erastin (IKE). Cystine and methionine limitation experiments confirmed that the sensitivity of EC to IKE is related to methionine metabolism. Inhibiting the activity or expression of major methionine metabolic enzymes markedly enhanced the cell death and oxidative stress levels of EC. The analysis results of multiple public datasets indicate that the expression of the major methionine metabolic enzymes is related to hepatocyte nuclear factor 4α (HNF4α). Chromatin immunoprecipitation (ChIP) and luciferase assays were employed to confirm the transcriptional regulatory role of HNF4α on the major methionine metabolic enzymes. Additionally, in vitro RNA interference experiments and in vivo xenograft mouse models verified that down-regulation of HNF4α abolished ferroptosis resistance in EC. In conclusion, HNF4α-mediated activation of methionine metabolism sustains cellular antioxidant capacity, thereby promoting ferroptosis resistance in epithelial HCC cells. These findings position HNF4α and major methionine metabolic enzymes as potential therapeutic targets to overcome ferroptosis resistance in HCC, offering a rational basis for more effective treatment strategies.
Zhou et al. (Tue,) studied this question.